1. Field of the Invention
The present invention relates generally to night vision goggles and, more particularly, to a night vision goggle system of improved construction, featuring prescription optics.
2. The Prior Art
Night vision goggles are binocular viewers that operate at very low light levels to allow the user to see and move in the dark. Night vision goggles represent a compromise among conflicting and competing requirements. They should be compact, light weight, cost effective and yet provide acceptable image quality.
Most known night vision goggles have traded compactness, cost effectiveness and weight in order to achieve acceptable image quality. For, it is in the design of the optics, more than in any other part of the goggles, that these competing requirements have to be worked out. Current designers, when faced with the requirement of providing a quality image for the goggles, have tended to think in terms of providing elaborate optics, both regarding the numbers and the quality of the lenses. For instance, present night vision goggles achieve two-eyed operation by means of two complete systems: an objective lens asssembly, an image intensifier tube and an eyepiece--one such system for each eye. Such elaborate optics, however, can only be achieved at the expense of adding to the size, weight and to the cost of the goggles.
There is thus a continuing need for night vision goggles that achieve a more favorable balance among these competing design considerations.